Interface for the Global Workspace module which contains Coalition objects and
implements a global conscious broadcast. It receives Coalition objects generated by AttentionCodelet objects
from Workspace. Different BroadcastTrigger tasks can be registered
dynamically. When a TriggerTask fires, all registered BroadcastListener modules
receive the content of the winning Coalition. Modules that receive the broadcast must
register themselves to this module and implement the BroadcastListener interface.